1. Field of the Invention
The present invention relates to a button including a button body and a tack member adapted to be joined with the button body for attachment of the button to a garment.
2. Prior Art
A known button comprises a button body and a tack member adapted to be joined with the button body for attachment of the button to a garment fabric. In attachment, a shank of the tack member is pierced through a garment fabric and is then forced through a hollow hub of the button body so as to deform or bend a tapering end of the shank, thus securing the latter to the hollow hub of the button body. However, in this prior button the tapering end portion of the tack member's shank is usually in the shape of a pyramid with its tip end disposed on the axis of the shank and hence requires relatively great force for the bending of the tapering end portion. This great force often causes not only the tack member's shank but also the button body's hollow hub to be objectionably deformed or otherwise damaged. Further, since the tip end of the pyramid-shaped end portion is disposed on the axis of the shank, the tip end would tend to penetrate into the back plate. As a consequence, accurate and firm joining of the tack member with the button body cannot be achieved.
Japanese Utility model Publication (Kokoku) 44-5791 discloses a tack member in which a shank has a lateral groove of square cross section near its tapering end portion so that the tapering end portion is bendable about the recess as the shank is inserted into a hollow hub of a button body. Another attempt has been made, as disclosed by Japanese Utility Model Publication (Kokoku) 12-6542, in which a shank has a plurality of lateral grooves of V-shaped cross section near its tapering end portion to facilitate bending. However, the groove or grooves of either Japanese Publication are formed by cutting, which makes the shank mechanically weak around such cutouts. With this structural weakness of the shank the tack member would tend to be easily deformed or bent back so as to be removed from the button body when a relatively great pulling force is exerted on the button.